The benefits of delivery vehicles that can release an active ingredient after a pre-determined lag time following ingestion are well known to the nutrition, supplement and pharmaceutical industries. Such delivery vehicles can be used to ensure the release of an active ingredient at a particularly advantageous time following ingestion e.g. a time approximating to a particular stage of digestion and/or the metabolic cycle and/or a particular location within the GI tract e.g. the duodenum, ileum or colon. Additionally, such delivery vehicles can be used to ensure the release of an active ingredient at a particular time of the day or night e.g. a time in-keeping with biological rhythms and circadian variations.
Of particular interest to the aforementioned industries are delivery vehicles that can release a lipid and/or lipophilic active ingredient within the GI tract after a pre-determined lag time.
Lipid and/or lipophilic active ingredients are known to be advantageously employed in the treatment or management of a variety of conditions affecting the health of the GI tract e.g. ulcerative colitis, Crohn's disease, colorectal cancer, and/or GI tract infections, as well as in the treatment and management of obesity and other weight related conditions e.g. through the modulation of hunger, satiety and/or through the regulation of nutrient absorption.
A delivery vehicle that can release a lipid and/or lipophilic active ingredient within the GI tract after a pre-determined lag time can not only increase the amount of said lipid and/or lipophilic active ingredient reaching a particular location within the GI tract, it can also minimise, prevent or control the metabolic modification or metabolism of said ingredient e.g. because of digestion and/or first pass effects. Accordingly, said delivery vehicle can improve the bio availability and/or efficacy of said lipid and/or lipophilic active ingredient, and consequently reduce its minimum effective concentration.
Delivery vehicles that can release an active ingredient within the GI tract after a pre-determined lag time following ingestion are known. A widely used delivery vehicle for this purpose is one in which an active ingredient is encapsulated in a matrix material. In this type of delivery vehicle an active ingredient is usually dispersed throughout a continuous matrix material that dissolves as it progresses through the GI tract. Typically the encapsulated active ingredient is intermittently released over a period of time as the matrix material surrounding the dispersed active ingredient is dissolved. This intermittent/slow release can be a drawback of these delivery vehicles. This is especially true in the case of an active ingredient that has a narrow absorption window or, in relation to an active that is intended to treat a condition affecting a particular location within the GI tract e.g. Crohn's disease, ulcerative colitis, colorectal cancer, and/or GI tract infections. For these cases in particular, a delivery vehicle that not only releases an active ingredient within the GI tract after a predetermined lag time but, also does so in a continuous and preferably rapid manner is particularly desirable.
Delivery vehicles that can release an active ingredient in a continuous and rapid manner are also known. The most widely used of these are delivery vehicles having an enteric coating. Enteric coatings form protective barriers around an active ingredient. However, enteric coatings have known drawbacks, for example the dissolution of enteric coatings at high pH and under conditions wherein there is a high water activity (AO, can make their application to emulsion based systems difficult e.g. those comprising lipid and/or lipophilic active ingredients. Furthermore, the dissolution of enteric coatings at higher pH values means that delivery of active ingredients within the GI tract is often restricted to the initial part of the small intestine Viz. the duodenum.
Accordingly, there remains a need for a delivery vehicle that avoids or mitigates one or more of the drawbacks and problems highlighted above.